Should the word locomotive be capitalized?

No, the word "locomotive" is not capitalized unless it is the first word in a sentence or part of a proper noun.

Here are some examples:

* Correct: The locomotive pulled the train across the countryside.

* Correct: The Locomotive Works is a historical landmark.

* Incorrect: The Locomotive is a powerful machine.

Remember, common nouns like "locomotive" are not capitalized unless they are used in a specific way.